export function string(o){
    return typeof o === 'string';
}

export function array(o){
    return Object.prototype.toString.apply(o) === "[object Array]";
}

export function object(o){
    return Object.prototype.toString.call(o) === "[object Object]";
}

export function date(o){
    return Object.prototype.toString.call(o) === "[object Date]";
}